This invention relates to an article classifying system for automatically measuring the width, length, thickness and weight of articles, e.g. pieces of mail, and comparing the measurements with preset values for various categories of mail to classify the mail pieces. This invention also relates to an apparatus for measuring dimensions of articles useable in such system.
Postal rates for mail pieces, e.g. letters, depend on the width, length, thickness and weight of the letters. When a clerk at a window of a post office receives the letter, he or she measures the dimensions with a ruler or a vernier micrometer to determine whether the letter is a standard-size. letter or nonstandard-size letter. Then, the clerk weighs the letter, and selects the postal rate for the letter from the list of rates predetermined on the basis of dimensions and weights.
Manual measurement of dimensions and weight of mail pieces has disadvantages, such as requiring time and labor and also possible errors in measurement. Such problems become obvious when handling a large quantity of mail. It is, therefore, desirous to eliminate such problems.
For sending mail for which postal rates are paid later in a lump sum, a sender sorts mail into standard mail and nonstandard mail, counts the numbers of pieces of standard and nonstandard mail, and writes the numbers down on a slip to be presented to a clerk at a window of the post office.
Standard mail is mail having dimensions, i.e. width, length and thickness within predetermined ranges of values and having weight less than a predetermined value, and nonstandard mail is mail other than the standard mail.
Manual sorting of mail pieces by senders into standard and nonstandard mail, counting the numbers of standard and nonstandard mail pieces and writing the numbers on slips may require a lot of time and labor and involve error.
Therefore, an object of the present invention is to provide a system for classifying articles, such as mail pieces, by automatically measuring their width, length, thickness and weight, and also to provide a dimension measuring apparatus useable in such system.
An article classifying system according to the present invention includes conveying means for conveying articles. Length measuring means, width measuring means and thickness measuring means measure the length, width and thickness of the articles conveyed by the conveying means, respectively. Weighing means weighs the articles. A plurality of categories are predetermined for articles according to length, width, thickness and weight of articles. Classifying means classifies measured articles into categories according to measurements of the length, width, thickness and weight of the articles.
The classifying means may classify articles as standard articles when the length, width, thickness and weight are within respective predetermined values for length, width, thickness and weight.
The article classifying system may include sorting means for sorting articles into standard and nonstandard articles in accordance with the classification made by the classifying means.
The article classifying system may further include counting means for counting the numbers of articles classified as standard and nonstandard articles by the classifying means, and printing means for printing out the numbers of the standard and nonstandard articles as counted by the counting means.
The article classifying system according to the present invention may further include sender reading means for reading representations of senders indicated on articles, and first calculating means for calculating the numbers of articles for respective senders.
The article classifying system may additionally include addressee reading means for reading representations of addressees indicated on articles, and second calculating means for calculating the numbers of articles for respective addressees.
The article classifying system may include, in addition to the addressee reading means, memory means for storing the addressees on articles as read by the addressee reading means together with the categories, e.g. standard or nonstandard, of such articles as classified by said classifying means.
The articles may be pieces of mail.
An article dimension measuring apparatus according to the present invention can measure the dimensions of an article having outward protruding side surfaces. For that purpose, it includes a light-emitting unit and a light-receiving unit. The light-emitting unit includes a plurality of light-emitters arranged in a measuring direction along the dimension to be measured. The light-receiving unit includes a plurality of light-receivers associated with the light-emitters and arranged along the same direction as the light-emitters. Each of the light-emitters is combined with two or more of light-receivers adjacent to each other to form an emitter-receiver combination. Each light-receiver belongs to two or more such combinations. The apparatus further includes detecting means for detecting whether light emitted by each light-emitter is not intercepted by the article and, therefore, is received by any one of the light-receivers in the emitter-receiver combination to which that light-emitter belongs. Computation means computes the dimension of the article, using the detection result provided by the detecting means, the distance between the light emitting unit and the light-receiving unit, and the distance between the light-emitting unit or light-receiving unit and a reference plane preset so as to pass substantial apexes of the outward protruding side surfaces of the article.
The light-emitters may be arranged along the dimension of articles to be measured, at equal intervals and in substantially the same plane, with the light-receivers arranged along the measuring direction at the same intervals as the light-emitters and in substantially the same plane which is in parallel with the plane in which the light-emitters are arranged. In this case, the distance between the reference plane to the light-emitting unit or to the light-receiving unit is the distance between the light-emitting unit and the light-receiving unit divided by an integer equal to or greater than two.